Positive Psychological States and Biological Processes

Mounting scientific evidence indicates that positive psychological states are reflected in biological processes, objective physical health, and mortality. This chapter examines the mechanisms through which positive psychological states influence physical health outcomes, focusing on biological processes. To that end, it first reviews the literature on the effect of positive psychological states on neuroendocrine and immune system function with a focus on hypothalamic-pituitary-adrenal (HPA) and inflammatory processes. Second, it describes a conceptual model of "enhanced allostasis" as a mechanism linking positive psychological states with physical health. Finally, it identifies questions that remain unanswered and outlines testable hypotheses guided by both existing literature and the enhanced allostasis model.